Start-up for 4/16/14 Create as many words as you can at least three letters long off of the following: SPECIATION

Objectives: Students will Biology Chapter 16-3, Pgs. 404-410 The Process of Speciation Objectives: Students will A) Define speciation. B) Identify and define the three types of isolation that leads to speciation. C) State the six steps to speciation. D) Summarize how episodic speciation, mass extinction, and biodiversity affects the survival of a species.

What is a SPECIES? A) Define speciation. Group of similar organisms Structurally biochemically Can interbreed successfully in nature Offspring are healthy Offspring are fertile (can reproduce)

These organisms are not new species…Why? A) Define speciation. These organisms are not new species…Why? Mule Liger

Tigon Result of male tiger and female lion mating in captivity. Offspring are infertile. Separated both geographically and ecologically.

Liger Result of male lion and female tiger mating in captivity. Offspring are infertile.

1) Evolution of new species from a single ancestor. A) Define speciation. Speciation 1) Evolution of new species from a single ancestor. 2) New species can no longer reproduce with original specie Results from: Isolation – 3 types Geographic, Behavioral, and Temporal

Table 23.1a

B) Identify and define the three types of isolation that leads to speciation. Divergent Evolution Isolated populations of a species evolve independently of each other. Ex – polar bears and brown bears

These squirrels live on opposite sides of the Grand Canyon These squirrels live on opposite sides of the Grand Canyon. This is an example of divergent speciation.

B) Identify and define the three types of isolation that leads to speciation. African Serval cat Convergent Evolution Natural Selection produces analagous (similar) adaptations in different organisms in response to similar environments: Ears, legs, acute hearing, habitat, and occupy similar niches American Maned wolf

Hawaiian Honeycreepers An example of adaptive radiation – evolution of many species from a common ancestor (founder species) Divergent or convergent? FOUNDER SPECIES

Divergent or convergent?

Reproductive Isolation B) Identify and define the three types of isolation that leads to speciation. . Reproductive Isolation results from Isolating mechanisms which include Behavioral Isolation Geographical Isolation Temporal Isolation produced by produced by produced by Behavioral Differences Physical Separation Different Mating Times which result in Independently Evolving Populations which result in Formation of new species

Understanding Check Which of these would have the least effect on natural selection in a subspecies of giraffes that is geographically isolated from other subspecies of giraffes? A available niches B existing predators C chromosome number D available food resources

4. Reproductive isolation occurs 5. Competition continues C) State the six steps to speciation. The 6 speciation steps How does this apply to Darwin's finches? 1. Founders Arrive 2. Isolation occurs 3. Gene pools change 4. Reproductive isolation occurs 5. Competition continues 6. Evolution continues

D) Summarize how episodic speciation, mass extinction, and biodiversity affects the survival of a species. Biodiversity Variety and abundance of a species in a community. Ensures specie survival Example: If the world freezes and 1000 varieties of birds exist = 1000 chances of 1 bird surviving disaster

STAR Prep According to this information, which group demonstrated the greatest biodiversity during the Cretaceous period? A dinosaurs B crocodilians C snakes D lizards

Episodic Speciation Is a sharp climatic shift D) Summarize how episodic speciation, mass extinction, and biodiversity affects the survival of a species. Episodic Speciation Is a sharp climatic shift Ice age, volcanic eruption, flooding, forest fire…. Results Mass extinction New pressures to adapt to new environment New open niches (habitats) Opportunity for surviving species to expand

D) Summarize how episodic speciation, mass extinction, and biodiversity affects the survival of a species. Mass Extinction Is a sharp decrease in number of species in a short time Affects most species present at that time Results = extinction and/or drop in speciation Example Cretaceous-Tertiary Extinction = Dinosaurs

Understanding Check – STAR Questions